I just recieved a drinking ticket?

I am from Iowa and just received a PAULA (Possession of alcohol under the legal age)...if I go to court what can I say to get out of it? Is there any way for this not to go on my record? My room mate had a serious misdemeanor (possession of a fake id) and it got expunged from his record if he didn't get caught for anything else which he didn't....how can I get that?? What should i do?